In the Administrative Overview section of NextCloud, the following warning appeared:

The PHP OPcache module is not properly configured. See the documentation for more information. The OPcache interned strings buffer is nearly full. To assure that repeating strings can be effectively cached, it is recommended to apply opcache.interned_strings_buffer to your PHP configuration with a value higher than 8.

Edit PHP.ini with Vim to adjust opcache.interned_strings_buffer and opcache.memory_consumption. E.g. Just increase their values for now, as follows:

Find and edit the php.ini file in the following directory:

cd /etc/php/8.1/apache2

ls

[to list php.ini file]

Use Vim to edit the php.ini file.

sudo vim php.ini

Change the value of the buffer from 8 to 16 Change the value of memory consumption from 128 to 256 By editing the following settings within the php.ini file

opcache.interned_strings_buffer=16
opcache.memory_consumption=256

Save and exit vim.

Restart the Apache2 service

sudo systemctl restart apache2

See whether the warning message, “the OPcache interned strings buffer is nearly full,” has disappeared from the nextcloud administration overview section. It should be gone, and all is well.